ads.txt and seller.json for Publishers

Publishers identify themselves to DSPs as authorized sellers by including an ads.txt and/or seller.json file on their inventory.

Verizon Media supports the industry-wide initiative. We are partnering with both DSP's and supply sources to facilitate the enforcement of ads.txt and seller.json files by our DSP partners.

What is ads.txt?

Ads.txt was created by the IAB to allow publishers to publicly declare the specific exchanges they work within the digital advertising space. The goal of ads.txt is to improve transparency and decrease fraud revenue.

How is the ads.txt file formatted?

The format for ads.txt file is: #< SSP/Exchange Domain >, < SellerAccountID >, < PaymentsType >, < TAGID >


#ads.txt file sample
 , 12000, DIRECT #banner, US, 3679, DIRECT #video, US, 20459933223, DIRECT # banner, US, 25980889636, DIRECT # banner, CA, 4577, DIRECT #banner, app

How do I include Oath in my file?

To include Oath in your file, publishers must have at least 3 of the 4 mandatory fields inserted into the .txt file that are hosted. Each field is separated by a comma and each company has its own line of code.

Field #1 - The domain you enter here depends on the platform being monetized.

Platform Domain
Oath Ad Platforms SSP
Oath Ad Platforms Video SSP
ONE by AOL: Display
DSP, Gemini

Field #2 - Enter your Publisher ID (the ID we assigned and you pass in the ad call). If you don’t know your ID or need help finding it, reach out to an Account Manager.

Field #3 - Enter the type of relationship.

  • Direct
  • Reseller

Field #4 - Optional, Oath's TAG ID is e1a5b5b6e3255540.

What happens next?

DSP’s actively crawl the web looking for ads.txt files and the data they contain. Oath’s code appearing in the file confirms that the inventory is held by an authorized seller.

*Note: ads.txt file information applies to all Oath platforms, not just the SSP.


Ads.txt FAQ’s

Q: What does ADS stand for?

A: Authorized Digital Sellers

Q: Which platforms could be impacted?

A: Ads.txt applies to all Oath platforms, SSP (mobile web & in-app inventory), Video SSP and DSP. Ads.txt is working to eliminate counterfeit or spoofed inventory and prevent the reselling of an unauthorized impression. This can impact all resellers on the above-listed supply platforms.

Q: For app ads.txt, is the platform domain the same as mobile web?

A: Yes! For example, is the domain for the Oath Ad Platforms SSP and it is the same for both mobile web and mobile app inventory. However, Oath does have other domains and depending on the publisher’s set up, 1 or more domains could be listed on an ads.txt file.

Q: For app ads.txt, what is the difference between the mobile web and mobile app implementation?

A: Mobile web ads.txt implementation is considered display and therefore follows the same specs. Mobile apps (Android, iOS, etc) use the new app-ads.txt specs. Apps that do not have desktop inventory must have a website created that can host the ads.txt file and add it to the developers section of the App Store.

Q: From a formatting perspective, what is the difference between ads.txt and app ads.txt root domain formats?

A: According to the IAB spec, “Publishers should post the "/ads.txt" file on their root domain and any subdomains as needed.” (Reference page 6 under the section called 3.1 ACCESS METHOD). Referencing the IAB specs for app ads.txt, append "/app-ads.txt" at the end of your domain. The main difference is “app-” is added to the app and not mobile web files.

Q: Does a non-authorized seller mean they have invalid traffic?

A: No, not necessarily. It may mean the inventory is being resold without the publisher's knowledge, the partner didn't get added to the ads.txt file in time for publication or was inadvertently left out. It could also mean the publishers decided to not participate.

Q: Can I see a current example of a live ads.txt file?

A: View examples of live ads.txt files at or

Q: What is the Certification Authority ID? Does Oath have one?

A: A Certification Authority ID uniquely identifies the advertising system (this ID maps to the entity listed in Field #1). The Certification Authority ID is optional and appears in Field #4.

Oath is certified for malware (as of September 2018) by the Trustworthy Accountability Group (aka TAG). Our TAG ID is e1a5b5b6e3255540. Use our TAG ID on your ads.txt file for our entries.

More info and examples can be found in the IAB OpenRTB ads.txt Spec on pages 6 & 8.

Q: Are ID’s consistent across Oath’s platform?

A: No, ID’s can vary from product to product as well as country to country. The Exchange/Seat ID would be the Publisher's Network ID in Oath Ad Platforms. If a Publisher is set up in both the US and EU, they must enter two lines in their ads.txt file - one for each Network ID.

Q: I work with you through a Header Tag (via Prebid), can I use the Publisher ID that corresponds to that integration?

A: Yes, the PubID is the same.

Q: Does the Oath exchange offer my inventory on other exchanges on my behalf?

A: Yes, we work with exchanges who are resellers. It is up to the publisher to authorize these resellers in their ads.txt file. We recommend working with your account manager to make sure the correct reseller information is included.

Q: Can I see a sample crawler for demand partners?

A: Yes, please reference the IAB page here.

Q: Do all SSP’s use publisher ID?

A: Most SSP’s use publisher ID; but that depends on the partner’s platform. We recommend you reach out directly to individual SSP’s.

Q: What are the code lines starting with the # symbol?

A: These are considered comments and are ignored by the system.

Q: Do you have an SSP sample bid request for mobile devices?

A: Yes, see the sample bid request below for mobile.

"publisher": {
       "id" : "17382",
       "Name" : "PRO12 Mobile",
       "Ext" : {
       "Nex_else" : 0

Q. Do you have an SSP sample bid request for display?

A: Yes, see the sample bid request below for display.

"site": {
     "id": "50-1234",
     "page": "",
     "publisher": {
     "id": "50"

Q: Is Oath actively crawling the web for ads.txt files?

A: Yes, we started crawling in September 2017.

Q: What happens if no ads.txt file is present?

A: DSPs can interpret the absence of ads.txt files in two ways:

  • Assume that no advertising is unauthorized because no file is present
  • Reach out to the publisher to get authorization to sell inventory

Q: What if DSPs want to target/exclude based on one or more of these options?

  • Authorized reseller
  • Non-Participating
  • Non-authorized reseller

A: Targeting (including or excluding seller’s inventory) is controlled by the DSP. Most DSP’s are making bid decisions based on the information they find in specific ads.txt files.

Still have questions? Reach out to your account manager.

Have more questions? Submit a request